218939378117 has 2 divisors, whose sum is σ = 218939378118. Its totient is φ = 218939378116.

The previous prime is 218939378111. The next prime is 218939378233. The reversal of 218939378117 is 711873939812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 129754125796 + 89185252321 = 360214^2 + 298639^2 .

It is a cyclic number.

It is not a de Polignac number, because 218939378117 - 2²⁸ = 218670942661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218939378111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109469689058 + 109469689059.

It is an arithmetic number, because the mean of its divisors is an integer number (109469689059).

Almost surely, 2^218939378117 is an apocalyptic number.

It is an amenable number.

218939378117 is a deficient number, since it is larger than the sum of its proper divisors (1).

218939378117 is an equidigital number, since it uses as much as digits as its factorization.

218939378117 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4572288, while the sum is 59.

The spelling of 218939378117 in words is "two hundred eighteen billion, nine hundred thirty-nine million, three hundred seventy-eight thousand, one hundred seventeen".